Science fiction writer needs help on sci-fi weapon

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Discussion Overview

The discussion revolves around the feasibility and implications of a hypothetical sci-fi weapon that utilizes a giant circular accelerator to launch a metal slug at extremely high velocities, potentially achieving kinetic energies on the order of 10^22 joules. Participants explore the physics of acceleration, the effects of such a projectile upon impact, and the differences between kinetic energy weapons and energy weapons.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether a circular accelerator can achieve a kinetic energy greater than 10^12 joules, suggesting that the construction would determine the outcome.
  • Another participant argues that a linear accelerator would provide double the velocity for the same force compared to a circular one, raising concerns about the practicality of the circular design.
  • A hypothetical scenario is presented where a slug with kinetic energy of 10^22 joules is questioned for its potential impact on a planet, with some skepticism about whether it could deliver that power.
  • Concerns are raised about the slug disintegrating upon impact due to its high velocity, with one participant suggesting it would create a significant hole but likely not match the destructive power of an H-bomb.
  • Another participant speculates that the energy released would be equal to the slug's kinetic energy, including the shock wave produced, which could be larger than the projectile itself.
  • Discussion includes the idea that mechanical waves dissipate energy over shorter distances than electromagnetic waves, potentially limiting the area of effect of the projectile.
  • One participant estimates that a slug of 600 metric tons would produce a recoil velocity on a massive ship, questioning the accuracy of their calculations and assumptions.
  • There is a discussion about the differences between recoil calculations for kinetic energy weapons and energy weapons, with participants seeking clarification on the appropriate formulas to use.

Areas of Agreement / Disagreement

Participants express a range of views on the mechanics and implications of the proposed weapon, with no consensus reached on the feasibility of achieving such kinetic energies or the resulting effects upon impact. Disagreements exist regarding the nature of energy transfer and the potential for destruction compared to nuclear weapons.

Contextual Notes

Limitations include assumptions about the mass and velocity of the slug, the effects of atmospheric entry, and the specific mechanics of energy transfer during impact. The discussion also reflects uncertainty about the appropriate equations for calculating recoil in different contexts.

  • #31
Why do you need inertial dampening?

First, if you do, there are ways around it. One of the rifles I own has the action free to slide backwards in the stock. i.e. only part of the weapon, and not the whole weapon, nor the whole ship, needs to recoil.

Second, it's not necessary to completely negate the recoil of the weapon. The A-10 aircraft has aboout 80 kN (kiloNewtons) of thrust and its cannon generates upwards of 45 kN of recoil when fired. The plane does not fall out of the sky, but does stagger in flight.

If the weapon is unfeasible I believe it is do with the fact that it's (in my opinion) a bit of a one trick pony and probably less effective than just blowing up a bunch of nuclear warheads.
 
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  • #32
There was a story by A C Clarke (perhaps Earthlight - it's a long time since I read it) about a similar weapon deployed in a war between Earth and Lunar mining colonists.
 
  • #33
rorix_bw first,if i had the magnetic accelerator absorb all or even most of the recoil and not the whole ship then I'm placing all of the force against less anchoring mass; i.e., the force that can cause my ship to recoil at 12Km/sec will accelerate the recoiling mechanism 100x faster. the weapon would tear itself through the ship and out the back.

second, if i don't have inertial dampering the sudden recoil acceleration would turn the crew into strawberry jam.

third, your A-10 aircraft does not have to worry about relativity complicating things.

but, yes you are right i should just use a bunch of nukes.
 
  • #34
i'm not going to do it. I'm comitted to the magnetically accelerated slug even if the nukes are more feasible option. I'm at the point where the storyline is more important. maybe the target race has fission damping technology that wouldn't allow nukes to work.
 
  • #35
schonovic said:
i'm not going to do it. I'm comitted to the magnetically accelerated slug even if the nukes are more feasible option. I'm at the point where the storyline is more important. maybe the target race has fission damping technology that wouldn't allow nukes to work.

Nukes could simply be a more *covert* means of mass destruction since you don't need a massive launcher and projectile, just a 300 pound small warhead. Also, your weapon doesn't have to be one round, it could fire a burst of rounds at less velocity and accomplish the same thing without destroying the weapon itself.
 
  • #36
Drakkith, thanks for the input. the multiple round option would make the weapon effective on other ships also.

anybody;what if i made the each successive magnet more powerful than the previous magnet? would that make a recoil mechanism effective with the larger slug? also i would counter thrust so no inertial dampering would be necessary.
 
  • #37
schonovic said:
Drakkith, thanks for the input. the multiple round option would make the weapon effective on other ships also.

anybody;what if i made the each successive magnet more powerful than the previous magnet? would that make a recoil mechanism effective with the larger slug? also i would counter thrust so no inertial dampering would be necessary.

I'm not sure what that would do. I don't think it would make the recoil easier to manage, probably the opposite actually. As long as the recoil isn't too high it can be managed. Another option is to increase the length of the "barrel" of the weapon and increase the time it takes to accelerate the object to your required speed. That would reduce the force delivered to the weapon/ship and make it easier to manage, plus make your counterthrusting more effective.
 
  • #38
schonovic said:
...what if i made the each successive magnet more powerful than the previous magnet?
Note that each successive magnet is going to be acting on a round that is moving successively slower, so there's no need for each one to be stronger than the last.
 
  • #39
DaveC426913 said:
Note that each successive magnet is going to be acting on a round that is moving successively slower, so there's no need for each one to be stronger than the last.

Why is the round moving slower?
 
  • #40
Drakkith said:
Why is the round moving slower?

Sorry. I misunderstood. Never mind.
 

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